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Merge 10.5 into 10.6

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Marko Mäkelä
2024-10-03 09:31:39 +03:00
parent cc70ca7eab 170e4555e2
commit 7e0afb1c73
482 changed files with 4427 additions and 623 deletions
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28
sql/opt_range.cc
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@@ -3531,9 +3531,35 @@ bool calculate_cond_selectivity_for_table(THD *thd, TABLE *table, Item **cond)
*/
selectivity_mult= ((double)(i+1)) / i;
}
table->cond_selectivity*= selectivity_mult;
selectivity_for_index.add("selectivity_multiplier",
selectivity_mult);
/*
Ok, now we assume that selectivity that range condition on
this index adds over selectivities on indexes that we've already
examined is
$SEL= (quick_cond_selectivity * selectivity_mult)
The heuristic that we used to obtain selectivity_mult may not be
correct (actually is known to be incorrect in simple cases), so
we make sure here that $SEL <= 1.0.
We adjust selectivity_mult (table->cond_selectivity was already
multiplied by quick_cond_selectivity above, so we will only
multiply it with selectivity_mult).
*/
if ((thd->variables.optimizer_adjust_secondary_key_costs &
OPTIMIZER_ADJ_FIX_CARD_MULT) &&
selectivity_mult > 1.0 / quick_cond_selectivity)
{
selectivity_for_index.add("note", "multiplier too high, clipping");
selectivity_mult= 1.0/quick_cond_selectivity;
selectivity_for_index.add("clipped_multiplier", selectivity_mult);
DBUG_ASSERT(quick_cond_selectivity * selectivity_mult <= 1.0);
}
table->cond_selectivity*= selectivity_mult;
}
/*
We need to set selectivity for fields supported by indexes.